EFFECT OF COIR FIBRE ON NR

1. EFFECT OF COIR FIBRE DUST AS FILLERS ON THE MECHANICAL
PROPERTIESOF NR VULCANIZATES
Under the guidance:
Dr. Sunil Jacob
DATE:19/07/2017
PRESENTED BY:
REG.NO:150011008037
Dinta
Sunny
MSc. POLYMER CHEMISTRY
CATHOLICATE COLLEGE COLLEGE,KOTTAYAM

2. REQUIREMENTS:
 NATURAL RUBBER (CONTINUOS PHASE)
 COIR FIBRE (DISPERSED PHASE)
 ZINC OXIDE (ACCELATOR)
 TDQ (ANTIOXIDANT)
 CBS (ACCELATOR)
 STERIC ACID (SOFTNER & FILLER DISPERSING AGENT)
 SULPHUR (VULCANIZING AGENT)

3. Coir Fibre Preparation
 NaOH Treatment
5% solution of NaOH added to 100g coir, stir well kept for 1 hr.Wash with distilled water
and acetic acid.Dried for 4 hr.
 Preparation of coir sheet
Different amount of coir fibre(10,20,30,40) was mixed with 100g NR.
This was passed between tight nip of a two roll mill to obtain a continuous sheet.
 Preparation of rubber mixes
Rubber mixes where prepared by mixing the ingredients in two roll mill as per ASTM
3182-82
 Two roll mixing mills for mixing all these and hydraulic press for vulcanization.

4. Determination of MECHANICAL Properties
 TENSILE STRENGTH =
𝑃
𝐵𝐷
OR
 TENSILE STRENGTH =
𝐿𝑂𝐴𝐷 𝐴𝑇 𝐵𝑅𝐸𝐴𝐾
𝐶𝑅𝑂𝑆𝑆 𝑆𝐸𝐶𝑇𝐼𝑂𝑁𝐴𝐿 𝐴𝑅𝐸𝐴
 Tear Strength =
𝐿𝑂𝐴𝐷
𝑇𝐻𝐼𝐶𝐾𝑁𝐸𝑆𝑆
 Hardness – Measured by shore A type durometer according to ASTMD 2240-03.
It’s value ranges between 0-100.
 Density – Measured using electrical kruss density meter DS-7800.Low wastage of
Sample.

5. 1. RESULTS OF TENSILE STRENGTH
Mixes
(phr)
Thickness
(mm)
Width
(mm)
Elongatio
n at
break %
Tensile
strength
Gum 2.310 3.000 396.220 2.021
NR 10 2.360 3.000 382.114 2.312
NR 20 2.410 3.000 362.104 2.521
NR 30 2.620 3.000 304.114 2.936
NR 40 2.490 3.000 330.200 2.864

6. Figure 3.1: Tensile strength of
GUM
0
0.5
1
1.5
2
2.5
0 50 100 150 200 250 300 350 400 450 500
Tensilestress(MPa)
Tensile strain (%)

7. 0
0.5
1
1.5
2
2.5
0 50 100 150 200 250 300 350 400 450
Tensilestress(MPa)
Tensile strain (%)
Figure 3.2: Tensile strength of NR-
Coir fibre composite with 10 phr fibre

8. 0
0.5
1
1.5
2
2.5
3
0 50 100 150 200 250 300 350 400 450
Tensilestress(MPa)
Tensile strain (%)
Figure 3.3: Tensile strength of NR-
Coir fibre with 20 phr fibre loading

9. 0
0.5
1
1.5
2
2.5
3
3.5
0 50 100 150 200 250 300 350
Tensilestress(MPa)
Tensile strain (%)
Figure 3.4: Tensile strength of NR-Coir fibre
composite with 30 phr fibre loading

10. 0
0.5
1
1.5
2
2.5
3
3.5
0 50 100 150 200 250 300 350 400
TENSILESTRESS(MPA)
TENSILE STRAIN (%)
Figure 3.5: Tensile strength of NR-
Coir fibre composite with 40 phr fibre

11. Mixes
(phr)
Thickness
(mm)
Load at
break
(B)
Tear
strength
(N/mm)
Gum
2.30 42.750 18.58
2.50 44.750 17.9
Mean 43.75 18.24
NR 10
2.350 45.575 19.393
2.370 45.775 19.314
Mean 45.675 19.353
NR 20
2.210 49.020 22.180
2.230 50.221 22.52
Mean 49.6205 22.35
NR 30
2.100 53.000 25.23
2.120 53.300 25.14
Mean 53.15 25.185
NR 40
2.220 51.662 23.271
2.240 51.862 23.152

12. 0
2
4
6
8
10
12
14
16
18
20
0 5 10 15 20 25 30 35 40 45 50
Tearstrength(N/mm)
Load (B)
Specimen 1 Specimen 2
Figure 3.5: Tear strength of
Gum material

13. 0
5
10
15
20
25
0 5 10 15 20 25 30 35 40 45 50
Tearstrength(N/mm)
Load (B)
Specimen 1 Specimen 2
Figure 3.6: Tear strength of NR-Coir
fibre composite at 10 phr fibre loading

14. 0
5
10
15
20
25
0 10 20 30 40 50 60
Tearstrength(N/mm)
Load (B)
Specimen 1 Specimen 2
Figure 3.7: Tear strength of NR-Coir
fibre composite at 20 phr fibre loading

15. 0
5
10
15
20
25
30
0 10 20 30 40 50 60
Tearstrength(N/mm)
Load (B)
Specimen 1 Specimen 2
Figure 3.8: Tear strength of NR-Coir fibre
composite at 30 phr fibre loading

16. 0
5
10
15
20
25
0 10 20 30 40 50 60
Tearstrength(N/mm)
Load (B)
Specimen 1 Specimen 2
Figure 3.9: Tear strength of NR-Coir
fibre composite at 40 phr fibre loading

17. DETERMINATION OF HARDNESS
Fibre Dust loading
(%)
Hardness
0 phr 25 shore A
10 phr 39 shore A
20 phr 50 shore A
30 phr 59 shore A
40 phr 62 shore

18. 0
10
20
30
40
50
60
70
0 phr 10 phr 20 phr 30 phr 40 phr
Hardness(ShoreA)
Fibre dust loading (%)

19. Shows variation of Density with fibre loading
Mixes
(phr)
Density
Gum 0.963
NR 10 0.972
NR 20 0.983
NR 30 0.996
NR 40 1.010

20. RESULTS AND CONCLUSIONS
 The tensile strength increased with increasing concentration up
to 30 phr and then declined. At intermediate levels of loading
(30 phr) the population of micro fibrils is just right for maximum
orientation, and the fibres actively participate in stress-transfer.
 As loading OF FIBRE IS increased, the tear strength would be
maximum at 30 phr. Sometimes at higher loading, the tear
strength decreased as the increased strain in the matrix between
closely packed micro fibrils increased tearing and reduced the
tear strength.
 The incorporation of microfibrils into NR matrix increased the
hardness of composite and is maximum at 40 phr .
 Due to close packing of micro fibrils , density was found to
increase

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New York, 1974
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